Silicone rubber compositions curable at room temperature are already known, and one-package system compositions and two-package system are commercially available.
Such silicone rubber compositions comprise as basic components a polydiorganosiloxane having a silanol group at the terminals, an organosilicon compound having a silicon-functional group and an inorganic filler, and undergo condensation reaction in the presence or absence of water and/or a catalyst to cure into rubber-like materials. Utilizing this property, those compositions are used as sealing materials or adhesives. However, since a sufficient adhesive strength cannot generally be obtained by the above-described basic components only, adhesion promotive agents (hereinafter referred to as "an adhesion promoter") are further added as a third component to improve the compositions so as to have adhesive strength enough for practical use.
H.sub.2 N(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3 HS(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3, [(CH.sub.3).sub.3 CO].sub.2 Si(OCOCH.sub.3).sub.2, CH.sub.2 .dbd.CHSi(OCH.sub.3).sub.3, HSi(OC.sub.2 H.sub.5).sub.3, and the like are known as such adhesion promoters. Although addition of such adhesion promoters serves to improve the initial adhesive property of the compositions, there is a disadvantage that a peel phenomenon is observed in an accelerated deterioration test, particularly a deterioration test in hot water or high temperature and high humidity atmosphere (hereinafter referred to as "hot water test" and "moist heat test", respectively).
As a method for improving the deterioration in hot water, there have been proposed a method in which a reaction product of an aminoalkylalkoxysilane with an epoxyalkyl-alkoxysilane is used as an adhesion promoter (JP-A-48-75633), a method in which (CH.sub.3 O).sub.3 Si(CH.sub.2).sub.2 C.sub.6 H.sub.4 CH.sub.2 NH(CH.sub.2).sub.2 NH.sub.2 is added (JP-A-60-60160), and a method in which a mixture of an amino-substituted silane and an epoxy group-containing silane is used (JP-B-63-23226). (The term "JP-A" and "JP-B" as used here in mean an "unexamined published Japanese patent application" and an "examined Japanese patent publication, respectively.)
However, the above prior art compositions also are still insufficient in adhesive property when they are evaluated by the moist heat test which is severer than the hot water test. Therefore, there has been a desire for a silicone rubber composition having good adhesive properties which are sufficient even when evaluated by both a hot water test and a moist heat test.